Technical Field
The present disclosure relates to computing devices and systems that include or operate in communication with a touch-sensitive surface.
Description of the Related Art
Modern computers are increasingly configured to receive and act on input from contact made with a touch-sensitive surface. For example, slate-shaped computers or tablet computers typically have a touch-sensitive display screen. A user may directly touch the screen with his or her finger to provide input to the computer. These computers may also be configured to receive input from a pen device used on the touch-sensitive screen to provide more precise input. With a pen device, a user is typically able to provide more detailed input than by way of touch contact alone. There are also touch-sensitive surfaces such as digitizers, separate from computer displays, that can be communicatively coupled to a computing device to provide input.
Often, when a user interacts with a touch-sensitive surface using a pen device, the user rests his or her hand on the surface while writing with the pen. Such hand contact with the touch-sensitive surface, however, frequently results in unintentional input to the computer, such as stray marks on a display as if the user had intentionally touched the surface with their finger, or inadvertent triggering of gestures, such as scrolling, rotating, or zooming on the display as if the user had intentionally provided multiple touch inputs to the surface. While unintentional contact typically comes from the user's hand that is holding a pen device, unintentional contact may also result from touches by other parts of the user's body such as the wrist or arm, or from objects situated near or on the user such as jewelry. In circumstances where the contact made with a touch-sensitive surface is not intentional, it is necessary to distinguish such contact with the touch-sensitive surface and reject the input resulting from such contact.